Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry..
What is the chemical formula for stickers. Please post any links about stickers and what makes them stick.
Friday, January 11, 2013 at 11:18pm

Chemistry..
1.What is going on at the atomic level if a precipitate forms in a double replacement reaction? 2. Has a single or double replacement reaction occured if water or a gas is formed? What would you perceive as evidence that a reaction has occured if either water or a gas is formed?
Friday, January 11, 2013 at 11:10pm

Chemistry PLEASE HELP:(
I really need someone to explain this stoichiometry problem. Directions: Outline how to determine the limiting agent. Determine the excess reactant and how much is left over. Determine the amount of each of the products produced. CaSO4 + AuF3 = CaF2 + Au2(SO4)3 Start with 15 ...
Friday, January 11, 2013 at 11:02pm

Chemistry
On more than one occasion when our kids were small, we would come inside from playing in the snow and I would make hot chocolate by heating the chocolate milk in the microwave. Invariably, I would get the milk too hot for at least one of them. One time, rather than adding more...
Friday, January 11, 2013 at 10:49pm

Chemistry
(a) A pressure vessel contains a large volume of CO2 gas at 10 atm pressure. A membrane composed of a poly(ether ketone) polymer with thickness 100 microns and net effective area of 100 cm2 covers a small perforated port in the container. The solubility of CO2 at 10 atm is 6....
Friday, January 11, 2013 at 10:48pm

Chemistry
A photon interacts with a ground state electron in a hydrogen atom and is absorbed. The electron is ejected from the atom and exhibits a de Broglie wavelength of 5.908 X 10^-10m . Determine the frequency (in hz) of the interacting photon.
Friday, January 11, 2013 at 10:39pm

Chemistry
(a) Silicon (50 g) has been doped with 27 mg of antimony (Sb). Determine the concentration of free charge carriers (carriers/cm3) at room temperature in this material. (b) Calculate the absorption edge of this material. Express your answer as a wavenumber in units of inverse ...
Friday, January 11, 2013 at 10:36pm

chemistry
mass of evaporating dish 22.34 mass of evaporating dish +hydrate 24.64 mass of evaporating dish +anhydrous salt 23.85 CuS04XH2O=CuSO4+XH2O 1.determine the mass of the water lost 2.determine the number of moles of the water lost
Friday, January 11, 2013 at 8:41pm

chemistry
At temperatures above 930 ∘C, PbO reduces PbS to form metallic lead (Pb). The byproduct of the reaction is SO2. Calculate the amount of lead produced (in kg) when a reactor is charged with 593.0 kg of PbS and 890 kg of PbO.
Friday, January 11, 2013 at 7:40pm

general chemistry
Identify and discuss the differences between the terms ‘theories,’ ‘laws,’ and ‘hypotheses.’ Describe ‘controlled conditions
Friday, January 11, 2013 at 7:32pm

Chemistry
The solubility of bismuth iodide (BiI3) in water is 10.291 x 10-3 M. Calculate the value of the solubility product. The dissolution products are Bi3+(aq) and I−(aq)
Friday, January 11, 2013 at 6:56pm

Chemistry
what type of reaction is AgF + CaCl2 --> AgCL + CaF2 ?
Friday, January 11, 2013 at 5:31pm

Chemistry
A photon interacts with a ground state electron in a hydrogen atom and is absorbed. The electron is ejected from the atom and exhibits a de Broglie wavelength of 0.468×10−10 m. Determine the frequency (in hz) of the interacting photon.
Friday, January 11, 2013 at 5:06pm

Chemistry
I have this question which I believe I solved correctly, but I was wondering if someone could look it over to make sure? The question is... Assay for Vitamin A (a fat soluble vitamin) required an extraction step into ether. In this assay, 2.00 mL of serum are extracted into 5....
Friday, January 11, 2013 at 2:50pm

Chemistry
HELP!!! At temperatures above 930 ∘C, PbO reduces PbS to form metallic lead (Pb). The byproduct of the reaction is SO2. Calculate the amount of lead produced (in kg) when a reactor is charged with 487.0 kg of PbS and 750 kg of PbO.
Friday, January 11, 2013 at 2:30pm

Chemistry
Consider a niobium single crystal. Which of the following directions has the largest Young's modulus? [100][110][111]
Friday, January 11, 2013 at 2:30pm

organic chemistry
malonic ester with urea gives
Friday, January 11, 2013 at 2:26pm

chemistry
A photon interacts with a ground state electron in a hydrogen atom and is absorbed. The electron is ejected from the atom and exhibits a de Broglie wavelength of 3.188*10^-10m Determine the frequency (in hz) of the interacting photon.
Friday, January 11, 2013 at 1:22pm

chemistry
The silicon wafer is coated with a layer of metallic aluminum which acts as an electrical contact. The x-ray diffraction pattern of aluminum is measured in a diffractometer with Fe Kα radiation. At what angle, θ, do you expect to observe the first reflection of ...
Friday, January 11, 2013 at 1:22pm

chemistry
(a) A pressure vessel contains a large volume of CO2 gas at 10 atm pressure. A membrane composed of a poly(ether ketone) polymer with thickness 100 microns and net effective area of 100 cm2 covers a small perforated port in the container. The solubility of CO2 at 10 atm is 6....
Friday, January 11, 2013 at 1:17pm

Chemistry
The solubility of bismuth iodide (BiI3) in water is 3.691 x 10-3 M. Calculate the value of the solubility product. The dissolution products are Bi3+(aq) and I−(aq)
Friday, January 11, 2013 at 12:53pm

Chemistry
A photon interacts with a ground state electron in a hydrogen atom and is absorbed. The electron is ejected from the atom and exhibits a de Broglie wavelength of 1.828×10−10 m. Determine the frequency (in hz) of the interacting photon.
Friday, January 11, 2013 at 12:47pm

Chemistry
At temperatures above 930 ∘C, PbO reduces PbS to form metallic lead (Pb). The byproduct of the reaction is SO2. Calculate the amount of lead produced (in kg) when a reactor is charged with 220.0 kg of PbS and 330 kg of PbO.
Friday, January 11, 2013 at 12:43pm

chemistry
(a) The solubility of bismuth iodide in water is 9.091 x 10-3 M. Calculate the value of the solubility product. The dissolution products are and
Friday, January 11, 2013 at 12:16pm

Chemistry
A pressure vessel contains a large volume of CO2 gas at 10 atm pressure. A membrane composed of a poly(ether ketone) polymer with thickness 100 microns and net effective area of 100 cm2 covers a small perforated port in the container. The solubility of CO2 at 10 atm is 6.97 x...
Friday, January 11, 2013 at 11:36am

Chemistry
The vacancy fraction of a particular metal is found to double as the temperature of the metal is increased from 700 degrees C to 850 degrees C. Calculate the enthalpy of vacancy formation for this metal. Express your answer in units of eV.
Friday, January 11, 2013 at 11:18am

chemistry
At temperatures above 930 ∘C, PbO reduces PbS to form metallic lead (Pb). The byproduct of the reaction is SO2. Calculate the amount of lead produced (in kg) when a reactor is charged with 553.0 kg of PbS and 830 kg of PbO.
Friday, January 11, 2013 at 10:45am

chemistry
) The solubility of bismuth iodide (BiI3) in water is 5.891 x 10-3 M. Calculate the value of the solubility product. The dissolution products are Bi3+(aq) and I−(aq)
Friday, January 11, 2013 at 10:31am

Chemistry
Calculate the surface energy of the (100) surface of niobium. The enthalpy of atomization of niobium is 745 kJ/mole. Express your answer in units of J/cm2.
Friday, January 11, 2013 at 10:27am

Chemistry
The rate constants for a first order decay reaction are found to be: k287.3∘C=1 x 10−4 s−1 k327.4∘C=19.2 x 10−4 s−1 (a) Determine the value, in s-1 of k250∘C (b) How long will it take, at 350 ∘C, for the reactant to decay to 1% ...
Friday, January 11, 2013 at 10:26am

Chemistry
Calculate the maximum wavelength of electromagnetic radiation capable of breaking the C-N bond in lysine. DATA: Average Bond Energies (kJ/mol) N-N 160 C-C 350 Express your answer in meters.
Friday, January 11, 2013 at 10:25am

chemistry
Tricky one- my math fails here (a) A pressure vessel contains a large volume of CO2 gas at 10 atm pressure. A membrane composed of a poly(ether ketone) polymer with thickness 100 microns and net effective area of 100 cm2 covers a small perforated port in the container. The ...
Friday, January 11, 2013 at 10:11am

Chemistry
At temperatures above 930 ∘C, PbO reduces PbS to form metallic lead (Pb). The byproduct of the reaction is SO2. Calculate the amount of lead produced (in kg) when a reactor is charged with 807.0 kg of PbS and 1210 kg of PbO
Friday, January 11, 2013 at 9:46am

CHEMISTRY
The vacancy fraction of a particular metal is found to double as the temperature of the metal is increased from 700 degrees C to 850 degrees C. Calculate the enthalpy of vacancy formation for this metal. Express your answer in units of eV.
Friday, January 11, 2013 at 9:45am

Chemistry
Shown above are images of two amino acids, along with the pKas of each of their titrateable groups. (a) Calculate the isoelectric point (pI) of the dipeptide Glycine-Arginine. unanswered (b) Calculate the isoelectric point (pI) of the dipeptide Arginine-Glycine.
Friday, January 11, 2013 at 9:03am

Chemistry
Answer the following questions by referencing the six stress-strain curves below. (a) Which of the stress-strain curves are for materials that are purely elastic? A B C D E F You have used 0 of 2 submissions 1.0 POINT (b) Which purely elastic material has the highest modulus? ...
Friday, January 11, 2013 at 9:03am

Chemistry
xplain why the value of the band gap energy, Eg, decreases in the following homologous series: Cdiamond=5.4 eV; Si=1.1 eV; Ge=0.72eV; Sn=0.08 eV. As we move down the group, bond strength increases. As the strength increases, materials become more metallic in nature, since ...
Friday, January 11, 2013 at 8:53am

To all the Chemistry spammers ...
anang, John, Prya, Sergey, Dylanprof, Amelia, kkr, kiril, Lena, c ~ Dumping ALL your homework questions in any one place (such as this website) is considered spamming. I've removed your collective 50+ posts except for those which received responses. Do not do this again.
Friday, January 11, 2013 at 8:48am

Chemistry
Shown below are several options for the box notations of the ground state electron configuration of the following gas-phase species. Identify the correct electronic configuration. i. Al2− ii. Mn (a)Select the reason that best explains why the first ionization energy ...
Friday, January 11, 2013 at 8:06am

Chemistry
Which is the higher density of polyethylene, linear or branched? Select the choice with the best accompanying explanation. Linear polyethylene is the higher density form, as the chains are able to pack better and partially crystallize, resulting in better packing and higher ...
Friday, January 11, 2013 at 8:02am

Chemistry
Identify the element that, acting as a target in an x-ray tube, generates Lα radiation of wavelength, λ, equal to 3.07 nm (3.07 x 10-9). Cu Ni Li Ti K Mo W
Friday, January 11, 2013 at 5:40am

chemistry
Shown below is a rough sketch of the unary phase diagram (pressure vs. temperature) for carbon dioxide (CO2), dry ice. Note the diagram is not drawn to scale and contains breaks in the axes to signify this. Using the diagram, answer the following questions: (a) Give the ...
Friday, January 11, 2013 at 5:39am

Chemistry
(a) What is the pH of 50 mL of a 0.2M glycolic acid aqueous solution after adding 5 mL of 0.25 M KOH? The pKa of glycolic acis is 3.83 at 25 ∘C.
Friday, January 11, 2013 at 5:30am

chemistry
The rate constants for a first order decay reaction are found to be: k287.3∘C=1 x 10−4 s−1 k327.4∘C=19.2 x 10−4 s−1 a) Determine the value, in s-1 of k250∘C (b) How long will it take, at 350 ∘C, for the reactant to decay to 1% of...
Friday, January 11, 2013 at 5:27am

chemistry
For AsClF42-: a) Name the hybridization of the orbitals of the central atom. s sp sp2 sp3 sp4 sp3d sp3d2 b) Estimate the Cl-As-F bond angle. Slightly less than 90∘ Exactly 90∘ Slightly greater than 90∘ Slightly less than 109.5∘ Exactly 109.5∘ ...
Friday, January 11, 2013 at 5:26am

chemistry
(a) What is the pH of 50 mL of a 0.2M glycolic acid aqueous solution after adding 5 mL of 0.25 M KOH? The pKa of glycolic acis is 3.83 at 25 ∘C.
Friday, January 11, 2013 at 4:47am

Chemistry
What is the mass of water that can be heated from 39 C to 80 C by the combustion of 150 g of methane. CH4 + 2O2 => CO2 + 2H2O Delta H= -890kJ
Friday, January 11, 2013 at 2:41am

Chemistry
Consider the following surfactants: (a) Which are nonionic surfactants? i) A ii) B iii)C iv) D v) E
Friday, January 11, 2013 at 2:41am

Chemistry
The energy versus bond length for the average bond in two solids, A and B, is shown below. Atoms in the two solids have the same number of nearest neighbots. (a) Which solid has the largest cohesive energy? A or B (b) Which solid has the smallest bond energy? A or B (c) Which ...
Friday, January 11, 2013 at 2:39am

Chemistry
Arginine O 2.01 H2N---CH--C----OH 9.02 CH2 CH2 CH2 NH 12.48 C==NH NH2 ________________________________________ 9.78 O 2.35 H2N----CH---C----OH CH3 Glycine ________________________________________ Shown above are images of two amino acids, along with the pKas of ...
Friday, January 11, 2013 at 2:35am

Chemistry
For each pair of compounds, identify the one with the higher boiling point. I)GeCl4 or SnCl4 II)PF3 or PF5 III)H2O or H2S
Friday, January 11, 2013 at 2:23am

Chemistry
(a) The solubility of bismuth iodide (BiI3) in water is 4.891 x 10-3 M. Calculate the value of the solubility product. The dissolution products are Bi^3+ (aq) and I^- (aq). (b) Do you expect the solubility of (BiI3) in 0.1 M NaCL (aq) to be equal to, greater than, or less than...
Friday, January 11, 2013 at 2:01am

Chemistry
Identify the element that, acting as a target in an x-ray tube, generates Lα radiation of wavelength, λ, equal to 3.07 nm (3.07 x 10-9). i) Cu ii) Ni iii) Li iv) Ti v) K vi) Mo vii) W
Friday, January 11, 2013 at 1:56am

Chemistry
(a) What is the distance between second nearest neighbor atoms in vanadium? Express your answer in cm. (b) What is the interplanar spacing between (110) planes in vanadium? Express your answer in cm. (c) At what angle must (110) planes of vanadium be exposed to a collimated ...
Friday, January 11, 2013 at 1:54am

Chemistry
Shown below is a rough sketch of the unary phase diagram (pressure vs. temperature) for carbon dioxide , dry ice. Note the diagram is not drawn to scale and contains breaks in the axes to signify this. Using the diagram, answer the following questions: (a) Give the pressure (...
Friday, January 11, 2013 at 1:53am

Chemistry
(a) Propylene, H2C=CH-CH3, can be reacted to form a polymer known as polypropylene (PP). What type of polymerization reaction is most appropriate for the formation of polypropylene? i)Addition Polymerization ii)Anionic Polymerization iii)Condensation Polymerization (b) What is...
Friday, January 11, 2013 at 1:41am

Chemistry
(a) What is the pH of 50 mL of a 0.2M glycolic acid aqueous solution after adding 5 mL of 0.25 M KOH? The pKa of glycolic acis is 3.83 at 25 Celsius. (b) Classify each of the following compounds as either "acidic", "basic", or "amphoteric" (able ...
Friday, January 11, 2013 at 1:35am

Chemistry
For AsClF4^2-: a)Name the hybridization of the orbitals of the central atom. i)s ii)sp iii)sp2 iv)sp3 v)sp4 vi)sp3d vii)sp3d2 b)Estimate the Cl-As-F bond angle. i)Slightly less than 90 ii)Exactly 90 iii)Slightly greater than 90 iv)Slightly less than 109.5 v)Exactly 109.5 vii)...
Friday, January 11, 2013 at 1:32am

Chemistry
The rate constants for a first order decay reaction are found to be: K287.3C = 1 X 10-4s-1 K327.4C = 19.2 X 10-4s-1 (a) Determine the value, in s-1 of K250C (b) How long will it take, at 350C, for the reactant to decay to 1% of its original concentration? Express your answer ...
Friday, January 11, 2013 at 1:22am

chemistry
Calculate the density of M&M’s given the following data: Mass of 250.0 mL beaker = 197.816 g Mass of beaker and 20 M&M’s = 342.816 g Volume of water in graduated cylinder = 8.0 mL Volume of water in graduated cylinder and 10 M&M’s = 18.5 mL (Points : 3)
Thursday, January 10, 2013 at 11:42pm

Chemistry
I have a Chemistry question which should be very simple but I do not know what significant figures are. Assuming the following numbers are measurements and using the rules for significant figures, determine the answer for the following calculation. (15.5/42)*219.5= 1. 81.0059 ...
Thursday, January 10, 2013 at 11:29pm

chemistry
what is the limiting reagent in a reaction between copper sulfate and barium nitrate?
Thursday, January 10, 2013 at 7:26pm

Chemistry
I've been working on this problem for hours and cant figure it out. I know it should be simple, but I'm stuck... The question is... Describe how to prepare 1.00L of a 1.0% (w/v) NaOH from a 2.0 M NaOH. *I need to figure out how many ml of the stock solution is needed. ...
Thursday, January 10, 2013 at 6:08pm

chemistry
A student is asked to prepare 250.0 mL of 3.5 M copper (II) sulfate from solid copper (II) sulfate pentahydrate. Describe how this solution should be made in the chemistry laboratory.
Thursday, January 10, 2013 at 5:49pm

chemistry
The solubility of strontium oxide, SrO, in water is 22.8 g per 100 mL at 100 °C and 0.69 g per 100 mL at 30 °C. Is the dissolving of strontium oxide in water an endothermic or exothermic process?
Thursday, January 10, 2013 at 5:21pm

chemistry??
Oxidising and reduction- Chemistry? Oxidation and reduction can be described as the loss and/or gain of electrons from an ion or atom (species) in a chemical reaction. For thefollowing aqueous reaction, select the species that is oxidized and similarly the one that is reduced...
Thursday, January 10, 2013 at 5:19pm

chemistry
what is the balanced equation for the reaction of potassium dichromate and potassium hydrogen phthalate?
Thursday, January 10, 2013 at 5:07pm

Chemistry
solid sodium reacts violently with water, producing heat, hydrogen gas, and sodium hydroxide. how many molecules of hydrogen gas are formed when 48.7 g of sodium are added to water? 2Na + 2H2O ------> 2NaOH + H2
Thursday, January 10, 2013 at 4:56pm

chemistry
molar enthalpy of combustion for pentane? Mass C5H12= 2.15g Mass H2O= 1.24kg Initial temp= 18.4°C Final temp= 37.6°C
Thursday, January 10, 2013 at 2:56pm

chemistry
What volume of oxygen at s.t.p is required for the complete combustion of methane according to the following equation. CH4 2O2= CO2 2H2O
Thursday, January 10, 2013 at 11:09am

chemistry
alternative reaction for acrylic acid and analyzing reaction for finding gross profit
Thursday, January 10, 2013 at 9:36am

chemistry please help
The reaction between hydrogen and chlorine gases gives hydrogen chloride gas in the following reaction: H2(g) + Cl2(g) = 2HCl(g) It is found experimentally that 1 mole of H2 gas reacts with 1 mole of Cl2 gas at constant temperature and pressure, to release 184 kJ of heat. What...
Thursday, January 10, 2013 at 6:41am

chemistry hellllllllllllllllllp
Oxidising and reduction- Chemistry? Oxidation and reduction can be described as the loss and/or gain of electrons from an ion or atom (species) in a chemical reaction. For the following aqueous reaction, select the species that is oxidized and similarly the one that is reduced...
Thursday, January 10, 2013 at 5:46am

Chemistry
How do you demonstrate that fog, clouds,and steam are liquid droplets and not water vapor?
Thursday, January 10, 2013 at 3:54am

Chemistry
Find the total number of calories needed to change 23.0 g of ice at -34.0C to steam at 222.0C
Thursday, January 10, 2013 at 3:29am

Chemistry
What is the equation to show that boiling is a cooling process?
Thursday, January 10, 2013 at 3:20am

chemistry
Strontium-90 decays through the emission of beta particles. It has a half-life of 29 years. How long does it take for 80% of a sample of strontium-90 to decay? Show process of how you got this
Thursday, January 10, 2013 at 1:16am

Chemistry
Solid aluminum carbonate decomposes to form solid aluminum oxide and carbon dioxide gas
Wednesday, January 9, 2013 at 11:42pm

chemistry
Suppose we want to charge a flask with 1.9 g of sugar. We put the empty flask on a balance and it is determined to weigh 170 g. Enter the weight we would expect to see on the balance when we're done adding the sugar.
Wednesday, January 9, 2013 at 10:47pm

AP Chemistry
The pH of a solution of Sr(OH)2 is 12.42. What is its pOH? What is its [H3O^+]? What is its (OH^-)? What is its [Sr(OH02]? Is the solution acidic or basic?
Wednesday, January 9, 2013 at 10:11pm

AP Chemistry
The pH of a solution of Sr(OH)2 is 12.42. What is its (OH^-)
Wednesday, January 9, 2013 at 10:09pm

Someone PLEASE HELP! (Chemistry)
Use the following problem to: Outline how to determine the limiting agent. Determine the excess reactant and how much is left over. Determine the amount of each of the products produced. CaSO4 + AuF3 = CaF2 + Au2(SO4)3 Start with 15 grams of each reactant.
Wednesday, January 9, 2013 at 10:07pm

chemistry
If 1.00 mole of BrCl is introduced into a 500.0 ml flask, what are the concentrations of Br2, Cl2 and BrCl at equailbrium
Wednesday, January 9, 2013 at 9:09pm

Chemistry
I have the same question as anonymous person before me so I just copy the question from that person, here is the question please help the two of us! if you have a mixture of sodium chloride and sodium bromide, could you use its conductance to determine the concentration of ...
Wednesday, January 9, 2013 at 9:07pm

Chemistry
please help sodium sulfate is soluble in water. How do you expect its conducatance to compare to sodium acetate at the same concentration? explain
Wednesday, January 9, 2013 at 8:49pm

Chemistry Urgent please help! Test tomorrow
if you have a mixture of sodium chloride and sodium bromide, could you use its conductance to determine the concentration of each solution? explain
Wednesday, January 9, 2013 at 8:48pm

chemistry
The half life of gold-197 is 10.6. What fraction of a sample remains after 21.2 years?
Wednesday, January 9, 2013 at 7:27pm

Chemistry
if you have a mixture of sodium chloride and sodium bromide, could you use its conductance to determine the concentration of each solute ?explain I am not sure of how to answer this question please some help!
Wednesday, January 9, 2013 at 7:20pm

Chemistry
please help, I don't know how to answer this question :( sodium sulfate is soluble in water. How do you expect its conducatance to compare to sodium acetate at the same concentration? explain
Wednesday, January 9, 2013 at 7:17pm

chemistry urgent urgent
the managing director of a company on wall street thrives on a diet of fruit jam,bread,pasta,and coffee.she exercises intermittently.one day she desides to go to her primary healthcare provider for a check up the provider recommends that she takes the benedicts test assume ...
Wednesday, January 9, 2013 at 6:52pm

Chemistry
A sample of gas occupies 24.5 L at a pressure of 1.57 atm; what is the pressure if the volume is increased to 48.3 L?
Wednesday, January 9, 2013 at 6:41pm

chemistry
Compounds like CCl2F2 are known as chlorofluorocarbons, or CFCs. These compounds were once widely used as refrigerants but are now being replaced by compounds that are believed to be less harmful to the environment. The heat of vaporization of CCl2F2 is 289 J/g. What mass of ...
Wednesday, January 9, 2013 at 5:23pm

chemistry
a 12.5 g sample of oxygen gas is added to a 25.og sample of nitrogen gas in a 25.0L'Container at 28 C. Calculate the partial pressure of each gas and the total pressure of he mixture. answer
Wednesday, January 9, 2013 at 2:03pm

chemistry
If 8 cm3 of 9.9 mol m-3 Fe(NO3)3 are mixed with 10 cm3 of 1.0 mol m-3 KSCN solution in a 20 cm3 volumetric flask and water is added to bring the total volume up to 20 cm3, what is the concentration of the Fe3+ ions (in mol m-3)?
Wednesday, January 9, 2013 at 1:33pm

chemistry
Carbonic acid, H2CO3, decomposes into water and a gas. Write the molecular equation for this decomposition. Remember to include the states of the reactants and products. Carbonic acid is an aqueous solution.
Wednesday, January 9, 2013 at 12:49pm

honors chemistry
Ammonia gas and hydrogen chloride gas from solid ammonium chloride. NH3(g),HCl(g) Balanced Equation:
Wednesday, January 9, 2013 at 12:46pm

chemistry
what is the frezzing point of 21.6 grams of NiSO4 in 1.00 times 10^2 H2O
Wednesday, January 9, 2013 at 12:36pm

chemistry
In the following reaction, how many grams of ammonia (NH3) will produce 300 grams of N2? 4NH3 + 6NO -> 5N2 + 6H2O
Wednesday, January 9, 2013 at 10:59am

chemistry
balance: Al2(CO3)3 --> Al2O3 + CO2 i dont know how to do the reactant side so i can figure out the product side...
Wednesday, January 9, 2013 at 9:24am

Chemistry
A reaction was performed in which 0.47 g of 2-naphthol was reacted with a slight excess of 1-bromobutane to make 0.29 g of 2-butoxynaphthalene. Calculate the theoretical yield and percent yield for this reaction. 2-naphthol + 1-bromobutane --> 2-butoxynaphthalene
Wednesday, January 9, 2013 at 2:53am

chemistry
i have to find the ratio of naoh:mass of KHP. but i have volume oh NaOH and mass of KHP and i dont know how to find the ratio then plz help me right now.
Wednesday, January 9, 2013 at 12:28am

Chemistry
An aqueous solution of HCl has a high electrical conductivity when compared to the compound in hexane, whilst the conductivity of a solution of the compound in diethyl ether has an intermediate value. Explain.
Tuesday, January 8, 2013 at 9:37pm

Chemistry
PLEASE PLEASE HELP How do i find the Empirical formula of CuCl2.5H2O
Tuesday, January 8, 2013 at 7:15pm

chemistry
How many atoms of carbon are in 325 g of tin (II) acetate?
Tuesday, January 8, 2013 at 6:59pm

chemistry
a sample of 20.0 mL of 0.100 M HCN (Ka=6.2*10^-10) is titrated with 0.150 M NaOH. a) what volume of NaOH is used in this titration to reach the equivalence point? b) What is the molar concentration of CN- at the equivalence point? c) What is the pH of the solution at the ...
Tuesday, January 8, 2013 at 6:35pm

chemistry
How many grams of oxygen are needed to burn 22.8 grams of C8H18? 80.0 g 240. g 40.0 g 20.0 g 120. g
Tuesday, January 8, 2013 at 3:54pm

chemistry
Calculate the enthalpy of reaction for the combustion of ethene. Express the enthalpy of reaction calculated in question above as a molar enthalpy of reaction per mole of carbon dioxide.
Tuesday, January 8, 2013 at 2:53pm

chemistry
so I don't expect you to answer all of these I just don't understand how they work so if someone could just explain one or two so I can do the rest that would be helpful! Thanks! Use the activity series to predict whether the following reaction will occur. Enter the ...
Tuesday, January 8, 2013 at 11:51am

chemistry
balance H2SO4 + NaOH --> H2O + Na2SO4 so i know you need 2 Na on each side but then I cant figure out the #'s for O or H
Tuesday, January 8, 2013 at 11:48am

chemistry
balance H2SO4 + NaOH --> H2O + Na2SO4
Tuesday, January 8, 2013 at 8:56am

Chemistry
2 ml of 1M HCl 0 ml of H2O 3ml of .3M Na2S2O3 How do I find the initial and final concentrations of both HCl and Na2S2O3?
Monday, January 7, 2013 at 10:10pm

Ap chemistry
How to calculate initial concentration, preferably with a general example??
Monday, January 7, 2013 at 9:45pm

chemistry
Ammonium nitrate will decompose explosively at high temperatures to form nitrogen, oxygen, and water vapor. 2NH4NO3(s) → 2N2(g) + 4H2O(g) + O2(g) What is the total number of liters of gas formed when 228g NH4NO3 is decomposed? (Assumed STP)
Monday, January 7, 2013 at 8:34pm

chemistry
Nitric acid and zinc react to form zinc nitrate, ammonium nitrate, and water. 4Zn(s) + 10HNO3(aq) → 4Zn(NO3)2(aq) + NH4NO3(aq) + 3H2O(l) A. How many atoms of zinc react with 1.49g HNO3? B. Calculate the number of grams of zinc that must react with an excess of HNO3 to ...
Monday, January 7, 2013 at 8:21pm

Chemistry
When 50.0g of silicon dioxide is heated with an excess of carbon 32.2 g of silicon carbide I'd produced. SiO2(s) + 3C(s) → SiC(s) + 2CO(g) A. What is the percent yield of this reaction? B. How many grams of CO gas are made?
Monday, January 7, 2013 at 8:14pm

Chemistry
Chlorine gas + aqueous sodium bromide --> aqueous bromine + aqueous sodium chloride. I got: Cl2+2NaBr2(aq)-> Br2(aq)+2NaCl2(aq) Is this right ?
Monday, January 7, 2013 at 4:52pm

chemistry
balance: CaCl2 + AgNO3 → AgCl + Ca(NO3)2
Monday, January 7, 2013 at 1:32pm

chemistry HWK MAKES NO SENSE
balance: H3PO4 + Mg(OH)2 → Mg3(PO4)2 + H2O
Monday, January 7, 2013 at 12:56pm

chemistry
If, in the reaction below, 31 g of C4H10 produces 41 41 g of CO2, what is the percent yield? Assume that the one reactant is limiting. 2C4H10 + 13O2 + 10H2O
Sunday, January 6, 2013 at 8:34pm

Chemistry
Calculate the mass of propane, C3H8(g), that must be burned in air to evolve the same quantity of energy as produced by the fusion of 1.0 g of hydrogen in the following fusion reaction: 4H ---> He + 2e- Assume that all the products of the combustion of C3H8 are in their gas...
Sunday, January 6, 2013 at 4:17pm

Chemistry
A number of antacid tablets contain water-insoluble metal hydroxides such as milk of magnesia, Mg(OH)2. Stomach acid is about 0.10 mol/L HCl(aq). Calculate the number of millimetres of stomach acid that can be neutralized by 500 mg of Mg(OH)2 (s).
Sunday, January 6, 2013 at 3:56pm

Chemistry
A radioactive element has a half-life of 6.41 days. What percent of the original sample will be left after 15.0 days?
Sunday, January 6, 2013 at 2:27pm

Chemistry
A solution of H2SO4 was electrolyzed using the inert platinum electrodes. A) Write the balanced half-reactions for the anode and cathode in this cell. B) How many coulombs passed through the cell in 90 minutes at 8.0 amperes? C) How many moles of electrons pass through the ...
Sunday, January 6, 2013 at 2:19pm

chemistry
smallest particle of a covalent compound?
Sunday, January 6, 2013 at 12:56pm

Chemistry
calculate the pH of a 0.2moldm-3 solution of ammonia at 298K given that Kb for ammonia is 1.8x10-5
Sunday, January 6, 2013 at 10:37am

chemistry
the heat of vaporization of liquid oxygen at 1.01325bar is 6820JMol at its boiling point,-183C, at that pressure. For the reversible vaporization of liquid oxygen calculate (a)q per mole (b) change in U (c) change in S (d) change in G
Sunday, January 6, 2013 at 9:47am

chemistry
0.1 mole of kmno4 react with excess of h2o2 then volume of o2 liberated
Sunday, January 6, 2013 at 8:22am

Chemistry
Describe and show your calculations on how you would prepare 1.00L of a 0.50M solution of each of the following a.) HCl from "concentrated" (12M) reagent. b.) Sodium Carbonate from the pure solid
Sunday, January 6, 2013 at 12:13am

chemistry
Describe and show your calculations on how you would prepare 1.00L of a 0.50M solution of each of the following a.) HCl from "concentrated" (12M) reagent. b.) Sodium Carbonate from the pure solid
Sunday, January 6, 2013 at 12:12am

chemistry
A student has a solution with a mole fraction of 0.20 of chloroform in carbon tetrachloride. What is the molality of chloroform in the solution?
Saturday, January 5, 2013 at 9:45pm

Chemistry
ow many molecules are in 0.26 mol of CO2?
Saturday, January 5, 2013 at 8:12pm

CHEMISTRY
What is the mass of 1.75 x 10^24 molecules of NH3?
Saturday, January 5, 2013 at 8:10pm

chemistry help plz
Le chatelier's principle? co(g)+cl2(g)=cocl2(g)is reversible and ,after a certain amount of time ,will reach equilibrium.Explain,using Le chatelier's principle,what effect: 1)increasing the pressure (at constant temperature) 2)increasing the temperature (at constant ...
Saturday, January 5, 2013 at 4:49pm

chemistry
how do you know that Al(OH)3(s) is a base?
Saturday, January 5, 2013 at 1:21pm

chemistry
can anyone give me 2 example of chiral molecules structure plz
Saturday, January 5, 2013 at 12:42pm

Chemistry
How many joules ar required to heat a frozen can of juice (360 grams) from -5 degrees C (the temp of an overcooled refrigerator) to 110 degrees C (the highest practical temp within a microwave oven)?
Saturday, January 5, 2013 at 12:36pm

Chemistry
Right, for the reaction of hot sodium hydroxide plus chlorine , how come one of the products are 5NaCl and not Na5Cl seeing as we now know the oxidation state of cl is -5
Saturday, January 5, 2013 at 9:32am

CHEMISTRY
(c) Calculate the degree of polymerization n of polystyrene with a molecular weight of 3.091×106 g/mol.
Saturday, January 5, 2013 at 6:03am

chemistry
(c) What is the value of the degree of polymerization n of isotactic PB with a molecular weight of 3.091×105 g/mol?
Saturday, January 5, 2013 at 5:51am

Chemistry
what is the bond length of sulfur trioxide?
Friday, January 4, 2013 at 9:52pm

Chemistry
Consider the following equilibrium at 395K: NH4HS(s) <--> NH3(g) + H2S(g) The partial pressure of each gas is 0.265 atm. Calculate Kc for the reaction
Friday, January 4, 2013 at 8:45pm

chemistry
For reduction of 1,4 dinitrobenzene when doing the equation I add h20 at end then count how many H's on right side which is 10 as 1,4diaminobenzene has 8, then on left there are 4H's on 1,4 dinitrobenzene. so that means you need 6(H). But how come in the actual ...
Friday, January 4, 2013 at 1:32pm

chemistry help !!!!!!!!!!!!!!!!
H2(g)+Cl2(g)=2HCL(g) it is found experimentally that 1 mole of H2 gas react with 1 mole of CL2 gas at constant temperature & pressure , to release 184kJ of heat .what is the enthalpy change for this reaction? ∆H=
Friday, January 4, 2013 at 1:20pm

chemistry help plz
what are the values of a,b,c and d in the balanced chemical equation aFe^2+(aq)+bAl(s)=cFe(s)+dAl^3+(aq) where a,b,c and d are the lowest possible whole numbers? a= b= c= d=
Friday, January 4, 2013 at 12:30pm

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